3/4-16 UNF Thread Specifications
Complete dimensions for 3/4-16 UNF (Unified National Fine) thread per ASME B1.1. TPI: 16, Pitch: 0.0625" (1.587 mm).
Thread Dimensions
| Designation | 3/4-16 UNF |
| Threads Per Inch (TPI) | 16 |
| Pitch | 0.0625" (1.587 mm) |
| Major Diameter | 0.75" (19.05 mm) |
| Pitch Diameter | 0.7094" (18.019 mm) |
| Minor Diameter (External) | 0.6733" (17.102 mm) |
| Minor Diameter (Internal) | 0.6823" (17.332 mm) |
| Thread Depth | 0.03383" (0.859 mm) |
| Tensile Stress Area | 0.37296 in² (240.6 mm²) |
Tap Drill Size
Recommended tap drill: 11/16" (0.6875" / 17.46 mm)
Calculated minor diameter (internal): 0.6823" (17.33 mm)
Proof Loads by SAE Grade
| Grade | Proof Stress (psi) | Tensile Strength (psi) | Proof Load (lbf) | Tensile Load (lbf) |
|---|---|---|---|---|
| Grade 2 | 55,000 | 74,000 | 20,513 | 27,599 |
| Grade 5 | 85,000 | 120,000 | 31,702 | 44,755 |
| Grade 8 | 120,000 | 150,000 | 44,755 | 55,944 |
Same Size, Different Series
Common Applications
- Structural steel, bridge connections, heavy equipment
- Fine thread applications